1. Field of the Invention
The present invention relates generally to a method of producing a hologram with an orthoscopic, and at least partially real image of an object, the object being recorded on a first hologram and the reconstruction of the object from this first hologram then being recorded on a second hologram.
2. Description of the Prior Art
A method of the mentioned type is known, e.g. from Appl. Phys. Letters 8, No. 6, March 15, 1966, pp. 146-148. The known method serves to produce real images which are orthoscopic. In ordinary holographic recording and reconstruction the real images are of course pseudoscopic (cf. e.g. "Funktechnische Arbeitablatter", Franzis Verlag Munich, Ot 91 "Holographie", Blatt 2). This sharply reduces the value of the real images although they have a great advantage over virtual images in that every point of the image can be examined as closely as desired, even with a magnifier if necessary. This deficiency is eliminated by the known method.
However the known method still has the drawback for the observer that the real orthoscopic image reconstructed from the second hologram can be viewed by the observer only over a limited angular range determined by the aperture of the first hologram reconstructed by the second hologram. If the observer's optical sensing device, usually his eye, leaves the mentioned angular region, then the image vanishes for no apparent reason.